SEVENTEEN-year-old To Tak-chi attributed his 10 A's score in this year's Hong Kong Certificate of Education Examination (HKCEE) to poverty, which left him with no money for entertainment. ''No entertainment means no distraction. It allows me to focus on my studies with solid determination,'' said the La Salle College student whose family lives on public assistance of just $5,000 a month. Tak-chi's humble statements should offer food for thought for those who care about the education of young people, whose overall academic performance has been on the decline in recent years. While Tak-chi did not intend to denigrate students from more affluent backgrounds who performed less admirably, his statements belie the observation by many youth workers that students are not as hard-working as their predecessors a generation ago because they are better off. With a lot more pocket money, they devote more of their time to going to the cinema and video game parlours rather than studying. Many also spend more time following showbiz idols and dating rather than in reading. Mr Rex King, formerly a secondary school principal and now Deputy Secretary of the Hong Kong Examinations Authority (HKEA), has ventured to suggest the territory's increasing affluence is a contributing factor of declining academic performance among young people. He said he found today's young people ''influenced by a changing teenage culture which puts more emphasis on enjoying the here and now and is less willing to make sacrifices to achieve academic excellence''. Although many Form Five students who performed poorly at the HKCEE still proceeded to retake the examination, the number of students doing so has dropped by 25 per cent in the past five years. During the same period, the number taking the London General Certificate of Education (GCE) examinations as an ''insurance policy'' also dropped from about 11,000 to 3,000, said Mr King, who has been running English tutorial classes on a voluntary basis for many years. He finds young people unable to concentrate for as long as their predecessors a decade ago. Mr Ng Tak-key, director of the student guidance centre of Hok Yau Club, which has been running a counselling hotline for school-leavers since 1982, shared Mr King's views. But he felt a main reason for the falling number of ''repeaters'' was the relaxation of criteria for admission to matriculation classes. Although public examinations by still caused stress among students, the pressure to excel had been reduced because of increased provision of higher education and good employment prospects in recent years, said Mr Ng. What worries the HKEA most is that the performance of students even at top schools dropped noticeably last year, causing the authority to tighten grading procedures across the board. The slippage was detected in tests administered to students of top schools in a control group which have been continuously assessed since 1982. The students' performances are a guide in establishing grading standards in subjects with large entries. ''Until very recently, there was no sign of any significant fall in standards. This year is the first year in which it has been necessary to tighten grading procedures across the board to maintain the standards represented by the traditional grades,'' said the Secretary of the HKEA, Mr Choi Chee-cheong. AS a result, the percentage of awards of grade E or above for all subjects fell by 2.2 percentage points, from last year's 62.9 to this year's 60.7. An even more worrying development is that the gap between the performance of the best and poorest students is widening. On the one hand, an increasing number of students at the top end of the ability range were able to score more and more distinctions by mastering the skills of passing examinations, such as by studying past papers and enrolling in tutorial classes run by former markers, said Mr Ng. On the other hand, the performance of the academically weak students remained poor and many achieved ''unclassified'' scores at public examinations, he said. Mr King said the weaker students failed because despite compulsory education, the system had changed little to accommodate them and they were attempting an examination that was academically beyond them. The use of English as the language of instruction in most secondary schools complicates the problem. ''Students are studying in schools where the medium of instruction is ostensibly English but where their teachers, for the sake of effective communication, are forced to rely mainly on Cantonese to teach despite the fact that textbooks, homework and tests all use English,'' said Mr King. ''This group then go on to enter for the English version papers of the HKCEE. Of the 30 bilingual subjects offered in the HKCEE, an astonishing 83 per cent of the subject entries are for the English versions - even though the certificates have given no indication of language medium since 1986.'' Mr King is particularly concerned that the weaker students can rarely be described as ''readers'' in the sense that they read comparatively little in either English or Chinese, and what they read, such as comics, is not educationally helpful. To accommodate the needs of weaker students, the HKEA is considering devising new modes of examination, including a modular approach, so that achievement at the lower levels can be more easily assessed and given recognition. Mr Ng commended the HKEA's initiative. He said the current examination system produced a strong sense of failure among students who were academically weak. Nevertheless, while changing the system and encouraging more schools to teach in Chinese would help, educators say the fact remains that affluence works against learning. The community may do better to consider how to motivate students to excel in their studies in an age when wealth is not necessarily seen to be associated with studying hard.